Communications networks, such as the Internet, are used increasingly to deliver a variety of services, including telephone communications, audio and video entertainment, financial transactions, and others. Such communications networks are subject to security risks, such as attempts by individuals or groups to inhibit the delivery of such services. Because of the number and amount of services delivered over communication networks, such security risks can have a large financial impact, both on service providers and their customers.
The use of the same reference symbols in different drawings indicates similar or identical items.